Antonyms of adj ineffective

3 senses of ineffective

Sense 1
ineffective (vs. effective), uneffective, ineffectual -- (not producing an intended effect; "an ineffective teacher"; "ineffective legislation")

effective (vs. ineffective), effectual, efficacious -- (producing or capable of producing an intended result or having a striking effect; "an air-cooled motor was more effective than a witch's broomstick for rapid long-distance transportation"-LewisMumford; "effective teaching methods"; "effective steps toward peace"; "made an effective entrance"; "his complaint proved to be effectual in bringing action"; "an efficacious law")
        => hard-hitting, trenchant -- (characterized by or full of force and vigor; "a hard-hitting expose"; "a trenchant argument")
        => impelling -- (markedly effective as if by emotional pressure; "impelling skill as a teller of tales"; "an impelling personality")
        => impressive, telling -- (producing a strong effect; "gave an impressive performance as Othello"; "a telling gesture")
        => rough-and-ready -- (crude but effective for the purpose at hand)

Sense 2
ineffective, ineffectual, unable -- (lacking in power or forcefulness; "an ineffectual ruler"; "like an unable phoenix in hot ashes")

INDIRECT (VIA impotent) -> potent, strong, stiff -- (having a strong physiological or chemical effect; "a potent toxin"; "potent liquor"; "a potent cup of tea", "a stiff drink")

Sense 3
ineffective, inefficient -- (lacking the ability or skill to perform effectively; inadequate; "an ineffective administration"; "inefficient workers")

INDIRECT (VIA incompetent) -> competent -- (properly or sufficiently qualified or capable or efficient; "a competent typist")

Similarity of adj ineffective

3 senses of ineffective

Sense 1
ineffective (vs. effective), uneffective, ineffectual -- (not producing an intended effect; "an ineffective teacher"; "ineffective legislation")
       => toothless -- (lacking necessary force for effectiveness; "a toothless piece of legislation")
       => unproductive -- (not producing desired results; "the talks between labor and management were unproductive")
          Also See-> idle#1; inefficacious#1; inefficient#1; powerless#1; useless#1

Sense 2
ineffective, ineffectual, unable -- (lacking in power or forcefulness; "an ineffectual ruler"; "like an unable phoenix in hot ashes")
       => impotent (vs. potent) -- (lacking power or ability; "Technology without morality is barbarous; morality without technology is impotent"- Freeman J.Dyson; "felt impotent rage")

Sense 3
ineffective, inefficient -- (lacking the ability or skill to perform effectively; inadequate; "an ineffective administration"; "inefficient workers")
       => incompetent (vs. competent) -- (not qualified or suited for a purpose; "an incompetent secret service"; "the filming was hopeless incompetent")